<p>ROME — A blaze on Friday at a small laboratory in central Italy that treats marijuana so it can be used medically left a man dead, three injured survivors and a woman missing, Italian firefighters said. </p>
<p>Flames raged through a small building in the countryside outside Gubbio, a town in the Umbria region. </p>
<p>Firefighters were searching into the night for a woman who was reported missing, said state firefighters spokesperson Luca Cari. Much of the fire had been extinguished, he said.</p>
<p>RAI state TV said the fire apparently was caused by a gas explosion. </p>
<p>Cari said it wasn’t immediately known what touched off the blast.</p>
<p>RAI state TV said that the most severely injured survivor was flown by helicopter to a hospital with a specialized burns center.</p>
